The present invention relates to an apparatus which is used to retain bone portions, such as vertebrae of a spinal column, in a desired spatial relationship.
A known apparatus for retaining vertebrae of a spinal column in a desired spatial relationship is disclosed in U.S. Pat. No. 5,613,968. U.S. Pat. No. 5,613,968 discloses an apparatus including a longitudinal member extendable along the spinal column. A fixation member connects the longitudinal member to a fastener connectable with a vertebra. A universal pad connects the fastener with the fixation member. The universal pad extends into the fixation member and the fastener extends through the universal pad. The universal pad has a protruding arcuate surface and a recessed arcuate surface concentric with the protruding arcuate surface. A clamping member is provided with a recessed arcuate surface engageable with the protruding arcuate surface on the universal pad. The fastener has a protruding arcuate surface engaging the recessed arcuate surface on the universal pad. The fastener is universally pivotable in any direction relative to the universal pad.
The present invention is an apparatus which is used to retain bone portions, such as vertebrae, in a desired spatial relationship. The apparatus includes a member connectable with a bone portion having an opening. A fastener which connects the member to the bone portion has a longitudinal axis. The fastener has a first end portion engageable with the bone portion, a second end portion extending through the opening in the member, and an intermediate portion engageable with the member between the first and second end portions. A connecting ring extends into the opening in the member and connects the member to the fastener.
The connecting ring has a passage with a longitudinal axis through which the second end portion of the fastener extends. The fastener is positionable in any one of a plurality of angular positions relative to the connecting ring so that the longitudinal axis of the fastener extends at any one of a plurality of angles to the longitudinal axis of the passage in the connecting ring. A clamping member engages the second end portion of the fastener and the connecting ring to connect the connecting ring to the member and connect the fastener to the connecting ring in any one of the plurality of angular positions relative to the connecting ring.